000
FXUS63 KFSD 011952
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
252 PM CDT SAT AUG 1 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 253 PM CDT SAT AUG 1 2015
NEBRASKA CONVECTION HAS PUT A DAMPER ON BOTH TEMPERATURES AND
CONVECTION CHANCES OVER MUCH OF THE FORECAST AREA TODAY. A STRONGER
THAN ANTICIPATED SHORTWAVE AND A SLOW TO WANE LLJ HAS KEPT
CONVECTION ONGOING NEARLY ALL DAY TO OUR SOUTH...WITH A PERSISTENT
FEED OF MID-UPRLVL CLOUDS INTO AREAS SOUTH OF I-90 TODAY.
12Z GFS/NAM/ECMWF NOT VERY MUCH HELP TODAY AT ALL...WITH ONLY MODELS
THAT SEEMED TO HAVE A CLUE BEING THE 00Z ARW/NMM WITH MORE RECENT
RUNS OF THE HRRR/HOPWRF CAPTURING THE TRENDS REASONABLY WELL.
THAT SAID...A SECONDARY SHORTWAVE CONTINUES TO TRACK SOUTHEAST
THROUGH NORTH DAKOTA THIS AFTERNOON...DEVELOPING A WEAK SFC LOW EAST
OF BISMARCK AND SENDING AN ELONGATED WARM FRONT SOUTHEAST INTO AREAS
NEAR THE MINNESOTA RIVER VALLEY EARLY THIS AFTERNOON. DEW POINTS
HAVE BEEN A STICKING POINT IN MODEL GUIDANCE THE PAST FEW DAYS...BUT
AT THIS POINT...SOLNS WITH LOWER FCST VALUES HAVE SEEMED TO DO
BETTER. SOUTHWEST OF THIS WARM FRONT OVER THE NORTHEASTERN HALF OF
THE CWA...TEMPERATURES HAVE BEEN SLOW TO RISE...AND DEW POINTS ARE
NOW MIXING DOWN INTO THE UPPER 50S TO LOWER 60S. GIVEN THE REMNANT
CAPPINGINVERSION ALOFT AOA 700MB...WE MAY BE HARD PRESSED TO
SUSTAIN ANY CONVECTION THAT DOES DEVELOP GIVEN THE POOR HEATING.
WILL CONTINUE TO MONITOR ELEVATED SHOWERS AND ISOLATED THUNDERSTORMS
OVER EASTERN SD AND FAR WESTERN MINNESOTA...WHICH SEEM TO BE ROOTED
ABOVE THIS ELEVATED MIXED LAYER. SHOULD SUFFICIENT MOISTUREPOOL
ALONG THE WARM FRONT...IT IS POSSIBLE TO HAVE A FEW STORMS DEVELOP
FURTHER AND BECOME SFC BASED INTO THE LATE AFTERNOON HOURS. STRONGER
ACTIVITY MAY STAY FAIRLY ISOLATED...WITH BEST FORCING AHEAD OF THE
SFC LOW IN EASTERN ND AND NW MN THIS EVENING AND ALONG A SECONDARY
FRONTAL BOUNDARY IN NORTHERN SD BEHIND THE SFC LOW. HIGHEST
INSTABILITY AND SVRWX RISKS WILL BE FOUND ALONG THESE
AFOREMENTIONED BOUNDARIES.
BY SUNDAY...A SECONDARY FRONTAL BOUNDARY WILL SLIDE THROUGH THE
REGION EARLY IN THE DAY...BRINGING GUSTY NORTHWEST WINDS AND MUCH
DRIER AIR. TEMPERATURES WILL STILL REACH ABOVE NORMAL BUT NO RAIN
IS ANTICIPATED.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 253 PM CDT SAT AUG 1 2015
SUNDAY NIGHT AND MONDAY SHOULD BE DRY AND MILD. THE TONE FOR THE
REST OF THE WEEK IS FOR A FLATTENING UPPER RIDGE..TEMPERATURES GOING
TO A LITTLE BELOW NORMAL...AND PERIODIC HARD TO TIME SHOWER AND
THUNDERSTORM ACTIVITY WITH A INCREASE IN MOISTURE AND THE PASSAGE OF
SHORT WAVES. THE MOISTURE RETURN FROM THE SOUTH WILL NOT BE QUITE AS
FAST AS EARLIER FIGURED AND HAVE HELD OF THE PRECIPITATION CHANCE
OVER THE SOUTHERN EDGE OF THE AREA UNTIL MONDAY NIGHT. THE INFLUX OF
MOISTURE WILL TAKE TIME TO GET TO THE NORTHEASTERN CORNER OF THE
AREA WITH WEDNESDAY THE FIRST PERIOD WE WILL HAVE SOME PRECIPITATION
MENTION OVER ALL OF THE AREA. MAINLY DUE TO THE TIMING
DIFFICULTIES...POPS WILL BE CHANCE AT MOST. WILL GO WITH THE
EXTENDED GUIDANCE ON A MENTION EACH PERIOD FROM WEDNESDAY ON FOR THE
SAME REASON AS ABOVE...TIMING IS TOO UNCERTAIN TO PIN DOWN ANY DRY
PERIODS ALTHOUGH A COUPLE OR THREE SEEM LIKELY FOR THE AREA.
AS HINTED AT ABOVE...TEMPERATURES FOR THE COMING WEEK WILL BE
TRENDING TOWARD THE OPPOSITE OF OUR RECENT WARM DAYS AND COOL NIGHTS
WITH THE CHANGE TO OVERALL NEAR NORMAL NIGHTS AND BELOW NORMAL
DAYTIME HIGHS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1214 PM CDT SAT AUG 1 2015
INFLUENCE FROM CONVECTION OVER NEBRASKA CONTINUES TO INFLUENCE THE
WEATHER FOR THE REMAINDER OF THE AFTERNOON/EVENING. THERE STILL
REMAINS A CHANCE FOR CONVECTION LATER TODAY...BUT PROBABILITIES
TOO LOW TO INCLUDE IN TAFS ATTM. VFR CONDITIONS WILL PERSIST INTO
THE OVERNIGHT HOURS...WITH A FEW WIDELY SCATTERED STORMS LATE THIS
EVENING POSSIBLE.
OTHERWISE...WILL WATCH A FRONT MOVE THROUGH MID-MORNING
SUNDAY...BRINGING GUSTY NORTHWEST WINDS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...DUX
LONG TERM...
AVIATION...DUX